Method for preparing imides from sulfonyl fluorides

ABSTRACT

This invention discloses a method for preparing imides (I) and (II) from compounds having a sulfonyl fluoride functional group. The imides so prepared are useful in a variety of catalytic and electrochemical applications. (I) or polymer comprising the unit (II)

This application claims the benefit of Provisional Application No.60/168,539, filed Dec. 2, 1999.

FIELD OF THE INVENTION

This invention is directed to a method for preparing imides fromcompounds having a sulfonyl fluoride functional group. The imides soprepared are useful in a variety of catalytic and electrochemicalapplications.

BACKGROUND OF THE INVENTION

Compounds having a sulfonyl fluoride functional group are well known inthe art. In particular, vinyl ethers and olefins having a fluorosulfonylfluoride group have been found to be particularly useful as monomers forcopolymerization with tetrafluoroethylene, ethylene, vinylidene fluorideand other olefinic and fluoroolefinic monomers to form polymers which,upon hydrolysis are converted to highly useful ionomers. One area ofimportant use for ionomers so formed is in the area of lithiumbatteries. See for example Connolly et all U.S. Pat. No. 3,282,875 andcommonly assigned Ser. No. 09/023,244 U.S. Pat. No. 6,025,092 and Ser.No. 09/061,132 U.S. Pat. No. 6,100,324.

It is also known to prepare imides from compounds having sulfonylfluoride functionality particularly fluorinated organic sulfonyl imidesare known in the art. For example, DesMarteau, U.S. Pat. No. 5,463,005,discloses substituted perfluoro-olefins of the formula

where X═CH or N, Z═H, K, Na, or Group I or II metal, R=one or morefluorocarbon groups including fluorocarbon ethers and/or sulfonyl groupsand/or perfluoro non-oxy acid groups, Y=perfluoroal or F, and m=0 or 1.

Xue, Ph.D. thesis, Clemson University, 1996, discloses the formation ofthe monomer

CF₂═CF—OCF₂CF₂SO₂N(Na)SO₂CF₃

by reaction of CF₂═CF—OCF₂CF₂SO₂Cl with CF₃SO₂NHNa in the presence ofNa₂CO₃ in acetonitrile. However, Xue's method is not applicable to thesulfonyl fluoride species without first protecting the double bond.

Further disclosed by Xue, op.cit, is CF₃SO₂NNa₂ made by combiningCF₃SO₂NHNa and NaH in THF and reacting for four hours at roomtemperature. The inventors hereof have determined that Xue's method ofpreparation provides a conversion of less than 10% from CF₃SO₂NHNa toCF₃SO₂NNa₂. No method of separation is provided, nor is any methodprovided for preparing the CF₃SO₂NNa₂ at higher yield. Thus no means isprovided for producing CF₃SO₂NNa₂ in a highly purified state. Xuesuggests that CF₃SO₂NNa₂ can be reacted with a cyclic sulfone of theformula:

to produce the vinyl ether monomer, CF₂═CF—OCF₂CF₂SO₂N(Na)SO₂CF₃. Alsodisclosed by Xue is a reaction between CF₂═CFOCF₂CF₂SO₂F and CF₃SO₂NHNato produce an unusable complex mixture of products. Xue makes nosuggestion that CF₃SO₂NNa₂ is effective at converting sulfonyl fluoridecontaining compounds to imides.

MeuBdoerffer et al., Chemiker Zeitung, 96. Jahrgang (1972) No. 10,582-583 discloses a method for synthesizing RSO₂NH₂ wherein R isperfluoroalkyl.

Feiring et al., WO 9945048(A1), provides a method for imidizingfluorinated vinyl ether monomers containing a sulfonyl fluoride group byfirst protecting the double bond and then converting the sulfonylfluoride into an imide.

Armand et al, EPO 0 850 920 A2, discloses a method for imidizingsulfonyl fluoride and chloride species containing aromatic rings.

SUMMARY OF THE INVENTION

The present invention provides for a process comprising: Contacting, ina liquid dispersion or solution, a composition comprising a sulfonylamide salt represented by the formula:

(R²SO₂NM_(b))_(3-b)M′_(c)  (III)

wherein R² is aryl, fluoro-aryl, or XCF₂— where X is H, halogen,fluorinated or non-fluorinated linear or cyclic alkyl radicals having1-10 carbons, optionally substituted by one or more ether oxygens, M′ isan alkaline earth metal, b=1 or 2, c=0 or 1, M is an alkaline earth whenb is 1 or an alkali metal when b is 2 and c=0, and M is alkali metalwhen b=1 and c=1, with the proviso that c is not equal to 1 when b=2with

a non-polymeric sulfonyl fluoride composition represented by the formulaR¹(SO₂F)_(m) (IV)

wherein m=1 or 2, where, when m=1, R¹ is a fluorinated ornon-fluorinated, saturated or unsaturated hydrocarbyl radical, exceptperfluoroolefin, having 1-12 carbons optionally substituted by one ormore ether oxygens, or tertiary amino; or, when m=2, R¹ is a fluorinatedor non-fluorinated, saturated or unsaturated hydrocarbylene, exceptperfluoroalylene, radical having 1-12 carbons optionally substituted byone or more ether oxygens;

or with a polymeric sulfonyl fluoride composition comprising monomerunits represented by the formula

—[CZ₂CZ(R³SO₂F)]—  (V)

wherein R³ is a diradical selected from the group consisting offluorinated or non-fluorinated allylene, including oxyalkylene orfluorooxyalkylene, but not perfluoroalkylene, and each Z isindependently hydrogen or halogen, and the Zs need not be the same; and,

causing them to react to form a non-polymeric imide compositionrepresented by the formula:

wherein y=1 or 2, M is an alkali when y is 1 or an alkaline earth metalwhen y is 2, m=1 or 2, where, when m=1, R¹ is a fluorinated ornon-fluorinated, saturated or unsaturated hydrocarbyl radical, exceptperfluoroolefin, having 1-12 carbons optionally substituted by one ormore ether oxygens, or tertiary amino; or, where m=2, R¹ is afluorinated or non-fluorinated, saturated or unsaturated hydrocarbylene,except perfluoroalkylene, radical having 1-12 carbons optionallysubstituted by one or more ether oxygens, with the proviso that when y=2and m=2, M may represent a combination of alkali and alkaline earthmetals;

or, in the alternative, a polymeric imide composition comprising monomerunits represented by the formula:

wherein y=1 or 2; R³ is a diradical selected from the group consistingof fluorinated or non-fluorinated alkylene, including oxyalkylene orfluorooxyalkylene, each Z is independently hydrogen or halogen, whereinthe Z's need not be the same; R² is aryl, fluoro-aryl, or XCF₂—where Xis H, halogen, fluorinated or non-fluorinated linear or cyclic alkylradicals having 1-10 carbons, optionally substituted by one or moreether oxygens; M is an alkali when y is 1 or an alkaline earth metalwhen y is 2.

As used herein, the term “reacting” is intended to mean allowing or toallow at least two components in a reaction mixture to react to form atleast one product. “Reacting” may optionally include stirring and/orheating or cooling.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 is a representation of the apparatus employed for determining thevolume of hydrogen gas evolved from the reactions described in thespecific embodiments herein.

DETAILED DESCRIPTION

The process of the present invention represents a simple method ofproviding a very wide range of imides which can be readily and variouslyion exchanged to provide superacid catalysts, electrolytes, and ionomersuseful for electrochemical applications.

In the practice of the invention it is not necessary to first protectthe double bond of an olefinic or vinyl ether prior to imidization. Theimidization will proceed without attacking the double bond.

Equally useful is the imidizationdblhapolymer comprising monomer unitsof vinylidene fluoride and monomer units comprising a pendant grouphaving sulfonyl fluoride functionality, particularly a perfluorovinylether perfluoroalkoxysulfonyl fluoride, such as described in Doyle etal., WO 9941292(A1). The methods of the art for converting sulfonylfluorides to imides are not applicable to the copolymers of WO9941292(A1) and others embodiments containing vinylidene fluoridemonomer units because of the base instability of the vinylidene fluoridemoiety. Application of the methods of the art result in extensive andunacceptable degradation of the polymer backbone in vinylidene fluoridecontaining polymers. The method of the present invention provides forconversion of sulfonyl fluoride to imide in vinylidene fluoridecontaining polymers without degradation of the polymer backbone.

In the present invention, the term “hydrocarbyl” is employed to mean amonoradical consisting of carbon and hydrogen. Included in the term“hydrocarbyl” are alkyl, cycloalkyl, aryl, aryl alkyl and the like.Similarly, the term “hydrocarbylene” is employed to mean a diradicalconsisting of carbon and hydrogen. Both hydrocarbyl and hydrocarbyleneradicals, as employed herein, may contain one or more unsaturatedcarbon-carbon bonds, one or more ether oxygens, and may be partially orfully fluorinated. Essentially any hydrocarbyl or hydrocarbylene radicalis suitable for the practice of the invention except that radicalscontaining perfluorolefin functionality are not suitable for thepractice of the invention. Perfluorovinyl ether functionality however ispreferred. Thus, the functional group CF₂═CF—CF₂— is not suitable butthe functional group CF₂═CF—O— is not only suitable but is alsopreferred.

In one aspect of the present invention, dimetal sulfonyl amide saltshaving the formula (R²SO₂NM_(b))_(3-b)M′_(c) (III) are found to behighly effective agents for preparing imides from a wide variety ofcompounds having a sulfonyl fluoride functionality, both from polymericand non-polymeric species. In the dimetal sulfonyl amide salts suitablefor the process of the invention, R² is aryl, fluoro-aryl, or XCF₂—where X is H, halogen, fluorinated or non-fluorinated linear or cyclicalkyl radicals having 1-10 carbons, optionally substituted by one ormore ether oxygens, M′ is an alkaline earth metal, b=1 or 2, c=0 or 1, Mis an alkaline earth when b is 1 or an alkali metal when b is 2 and c=0,and M is alkai metal when b=1 and c=1, with the proviso that c isunequal to 1 when b=2.

Preferably, R² is fluoroalkyl having 1-4 carbons; most preferably R² isCF₃—. Preferably, M is an alkali metal, most preferably sodium, and b=2.

In one embodiment, a non-polymeric sulfonyl fluoride compositionrepresented by the formula R¹(SO₂F)_(m) in liquid dispersion or solutionis contacted with the dimetal sulfonyl amide salt(III) to form areaction mixture. m=1 or 2, where, when m=1, R¹ is a fluorinated ornon-fluorinated, saturated or unsaturated hydrocarbyl radical having1-12 carbons optionally substituted by one or more ether oxygens, exceptperfluoroolefin, or tertiary amino; or, when m=2, R¹ is a fluorinated ornon-fluorinated, saturated or unsaturated hydrocarbylene, exceptperfluoroalkylene, radical having 1-12 carbons optionally substituted byone or more ether oxygens, preferably m=1. More preferably m=1, R¹ is aperfluorovinyl ether represented by the formula:

 CF₂═CF—O—[CF₂CF(R⁴)—O_(z)]_(n)—CF₂CF₂—

wherein R⁴ is F or perfluoroalkyl having 1-4 carbons, z=0 or 1, andn=0-3. Most preferably m=1 and R⁴ is trifluoromethyl, z=1, and n=0 or 1.

In one embodiment, the process of the invention may be conducted in theabsence of an inert liquid diluent when a sufficient excess of a liquidR¹(SO₂F)_(m) is provided to ensure good mixing. However, in the absenceof an inert diluent, the reaction may proceed inhomogeneously, and ispotentially subject to sudden decomposition. Therefore, it is preferredto conduct the process of the invention in an inert liquid diluent.Numerous aprotic organic liquids are suitable for use as an inert liquiddiluent for the process of the invention; the requirements are notstrict beyond liquidity and inertness. It is preferred to use a solventthat dissolves the monomer but not the NaF by-product so that it caneasily be filtered off. Preferred liquids are ethers, including THF,nitrites, DMSO, amides, and sulfolanes. Ethers are more preferred, withTHF most preferred.

The reaction may be conducted at any temperature between the freezingand boiling point of the inert liquid diluent. Room temperature has beenfound to be satisfactory in the preferred embodiment of the invention.Temperatures from room temperature to 80° C. are suitable, with roomtemperature to 60° C. more preferred.

The reaction mixture is preferably stirred or otherwise agitatedaccording to means commonly employed in the art.

In a first preferred embodiment of the process of the invention, theproduct of the process is most preferably as represented by the formula:

CF₂═CFO—[CF₂CF(CF₃)—O]_(n)—CF₂CF₂SO₂N(Na)SO₂CF₃  (VIII)

where n=0 or 1. It is a particularly surprising aspect of the presentinvention that the conversion of the —SO₂F group may be effected withoutthe necessity of protecting the double bond. The product so-formed,(VIII), may advantageously be employed as a comonomer with fluorinatedolefins, non-fluorinated olefins, fluorinated vinyl ethers,non-fluorinated vinyl ethers, and combinations thereof. Preferredcomonomers include ethylene, tetrafluoroethylene, hexafluoro-propylene,perfluoroalkyl vinyl ether, vinylidene fluoride, and vinyl fluoride.Copolymerizing the monomer (VIII) with a variety of co-monomers may beeffected for example according to the teachings of DesMarteau, op.cit.or of Feiring et al., op.cit. or, more broadly, may be effectedaccording the methods of Connolly et al., op. cit. The ionomers soformed are useful in a wide variety of electrochemical applications.

One area of particular utility is in lithium batteries. For thispurpose, the product monomer, (VIII), may be ion exchanged to thelithium form by contacting the monomer (VIII) with a dilute solution ofLiCl in THF. The polymerizations indicated above may then be effected.In the alternative, the polymerizations may first be effected, followedby ion exchange with LiCl in THF. In an alternative embodiment, thepreferred sodium imide of the invention can be treated with aqueous acidto form the acid followed by treatment with aqueous lithium salt to formthe lithium ion composition.

In a further embodiment a sulfonyl fluoride polymer composition iscontacted with the dimetal sulfonyl amide salt (III) in liquiddispersion or solution to form a reaction mixture. The polymer comprisesmonomer units represented by the formula

—[CZ₂CZ(R³SO₂F)]—  (V)

wherein R³ is a diradical selected from the group consisting offluorinated or non-fluorinated alkylene, but not perfluoroalkylene,including oxyalkylene or fluorooxyalkylene, and each Z is independentlyhydrogen or halogen, and need not be the same. Preferably, R³ isoxyalkylene. In a second preferred embodiment (V) is represented by theformula:

wherein R⁴ is F or perfluoroalkyl having 1-4 carbons, z=0 or 1, anda=0-3. Most preferably R⁴ is trifluoromethyl, z=1, and a=0 or 1.

The polymer comprising the moor units (IX) may comprise up to 50 mol %of said monomer units (IX). Comonomer units incorporated therewith maybe derived from numerous olefinically unsaturated species as identifiedin the art including, ethylene, vinylidene fluoride (VF₂) vinylfluoride, and combinations thereof to form terpolymers. Additionaltermonomers include tetrafluoroethylene, hexafluoropropylene,perfluoroalkyl vinyl ethers, and such other ethylenically unsaturatedspecies as are known in the art.

Particularly preferred for the practice of the invention is a copolymercomprising up to 50 mol %, most preferably up to 20 mol %, of comonomerunits (IX) and comonomer units derived from VF₂, most preferably atleast 50 mol % of monomer units derived from VF₂. It is a surprisingaspect of the present invention that the copolymer of (IX) with at least50 mol % of units derived from VF₂ can be successfully reacted accordingto the process of the invention to form the corresponding imide. Becauseof the well-known base instability of VF₂-containing polymers, themethods of the art for forming imides from sulfonyl fluorides are notoperable with polymers having any more than trace amounts of monomerunits derived from VF₂ because the imidizing agents of the art attackthe polymer backbone causing extensive degradation.

There is no particular limitation on the molecular weight of polymerssuitable for the practice of the invention. Oligomeric polymers maythemselves be liquids at or near room temperature and therefore arewell-suited as the liquid dispersing medium of the process. However, itis generally preferred to employ an inert diluent, preferably a solventfor the polymer. As the molecular weight of the polymer increases,solubility and solution viscosity become increasingly difficultproblems, making homogeneous reaction difficult. The preferred copolymerof VF₂ and comonomer (IX) is particularly well-suited to the practice ofthe present invention because of the relatively higher solubility ofVF₂-containing polymers in non-fluorinated solvents than otherfluoropolymers.

Numerous aprotic organic liquids are suitable for use as solvents forthe sulfonyl fluoride polymer composition in the process of theinvention. As stated, solubility of the polymer reactant is a limitingfactor. Preferred solvents are ethers, including THF, nitriles, DMSO,amides, and sulfolanes. Ethers are more preferred, with THF mostpreferred. Because of the limitations on solubility associated with highmolecular weight, lower molecular weight polymers are preferred.

Suitable and preferred reaction temperatures are as in the case of thenon-polymeric reactant hereinabove described.

For the purposes herein, the polymer produced in the process of theinvention is represented by the formula:

wherein y=1 or 2; R³ is a diradical selected from the group consistingof fluorinated or non-fluorinated alkylene, including oxyalkylene orfluorooxyalkylene, each Z is independently hydrogen or halogen, whereinthe Zs need not be the same; R² is aryl, fluoro-aryl, or XCF₂— where Xis H, halogen, fluorinated or non-fluorinated linear or cyclic alkylradicals having 1-10 carbons, optionally substituted by one or moreether oxygens; M is an alkali when y=1 or an alkaline earth metal wheny=2. When y=2, M is an alkaline earth metal. Setting y=2 is meant todesignate that the alkaline earth metal, M in (II), which has a valenceof 2, is bonded to two different polymer chains each of the indicatedcomposition, thus serving as a metallic cross-link. It is also possible,depending upon chain configuration, for the alkaline earth metal M to bebonded to two segments of the same polymer chain.

The process of the present invention is preferably practiced with apurified form of the dimetal sulfonyl amide salt (D). Xue, op.cit.,teaches only a process which provides very small amounts of highlycontaminated (II). The inventors of the present invention havedetermined by ordinary methods of chemical analysis that Xue's processproduced CF₃SO₂NNa₂ with conversion of less than 10%, most of theremainder of his reaction product being unconverted starting material.No method is provided in the art for preparing (III) in pure form.

In the process of the invention, the dimetal sulfonyl amide saltstarting material (R²SO₂NM_(b))_(3-b)M′_(c), (III), should first itselfbe produced at high yield. In (III), R² is aryl, fluoro-aryl, or XCF₂—where X is H, halogen, fluorinated or non-fluorinated linear or cyclicalkyl radicals having 1-10 carbons, optionally substituted by one ormore ether oxygens, M′ is an alkaline earth metal, b=1 or 2, c=0 or 1, Mis an alkaline earth when b=1 or an alkali metal when b=2 and c=0, and Mis alkali metal when b=1 and c=1, with the proviso that c is not equalto 1 when b=2.

Preferably, M is an alkali metal and c=0, b=2, and R² is aperfluoroalkyl radical. Most preferably M is sodium and R² is atrifluoromethyl radical. The inventor hereof has found that surprisinglydimetal sulfonyl amide salt (III) can be made at much higher puritiesthan in Xue's process, purity of greater than 50%, preferably greaterthan 90%, most preferably greater than 95%, by contacting a sulfonylamide or monometal sulfonyl amide salt thereof having the formula(R²SO₂NH)_(3-a)M″, (VII), with at least one alkali or alkaline earthmetal hydride and an aprotic liquid to form a reaction mixture which ispermitted to react to any desired degree of conversion up to 100%, whichis preferred. In the sulfonyl amide or monometal salt thereof (VII), a=1or 2, M″ is alkaline earth metal when a=1, M″ is alkali metal orhydrogen when a=2, and R² is aryl, fluoro-aryl, or XCF₂— where X is H,halogen, or a fluorinated or non-fluorinated linear or cyclic alkylradical having 1-10 carbons, optionally substituted by one or more etheroxygens. In the hydride may be a mixture of more than one alkali oralkaline earth hydrides, or a mixture of alkali and alkaline earthhydrides. If preferred, the reaction may proceed in stages withdifferent hydrides being fed to the reaction at different times.

Preferably R² is perfluoroalkyl, most preferably trifluoromethyl, and M″is sodium. CF₃SO₂NH₂ is the preferred starting material for preparingthe CF₃SO₂NNa₂ preferred for the process of the present invention. Thepreferred aprotic liquid is acetonitrile. Preferably the reaction toproduce the CF₃SO₂NNa₂ is continued until one or the other startingmaterial is completely consumed and reaction stops. More preferably thestoichiometry is adjusted so that only trace amounts of either startingmaterial remain when reaction is complete. Most preferably, the hydrideis added at slightly below stoichiometric quantity.

The sulfonyl amide and monometal salt thereof (VII) are soluble in theaprotic solvents employed in the process of preparing the dimetalsulfonyl amide salt (III), but the dimetal sulfonyl amide salt (III)itself is not. The solubility difference is exploited herein to separatethe reaction product from the reaction mixture and obtain a compositioncomprising sulfonyl amide salts at least 50 mol %, preferably at least90 mol %, most preferably at least 95 mol %, of which salts arerepresented by the formula (R²SO₂NM_(b))_(3-b)M_(c)′, (III), ashereinabove defined. Any convenient method known in the art forseparating solids from liquids may be employed, including filtration,centrifugation and, distillation.

While it is preferred to permit the synthesis of (III) to run tocompletion, this may not always be practical depending upon the aproticsolvent chosen. In neat acetonitrile, 100% conversion is achieved in ca.4 hours at room temperature. However, in neat THF, six days of reactionare required for 100% conversion. In the latter case, it may be desiredto separate the reaction product before the reactants have fullyreacted. The method of separation based upon the heretofore unknownsolubility difference hereinabove described provides a practical methodfor isolating the dimetal sulfonyl amide salt (III) at high purity whenconversion has been low.

It has been found in the practice of the present invention that residualhydride left over from the synthesis of the dimetal sulfonyl amide salt(III) is not highly deleterious to the efficacy of the process of thepresent invention. While not critical, the CF₃SO₂NNa₂ preferred for theprocess of the present invention is substantially free of contaminationby NaH. This is achieved by employing slightly less than thestoichiometric amount of NaH in its preparation, thereby insuring thatwhen the reaction achieves full conversion, the NaH will be exhausted.Any excess of the soluble intermediate CF₃SO₂NHNa is easily separated bywashing/filtration cycles, preferably using fresh aliquots of solvent.

In preparing the dimetal sulfonyl amide salt, (III) it has been foundthat the components of the reaction mixture may be combined in anyorder, but that it is preferred to first mix the sulfonyl amide or amonometal salt thereof (II), with the aprotic liquid to form a solution,following with addition of the hydride after the solution has formed.First mixing the hydride with the aprotic solvent has resulted in poorreaction or slower than expected conversion.

A suitable temperature for preparing the dimetal sulfonyl amide salt(III) will lie between the melting point and the boiling point of theaprotic liquid selected. It has been found to be satisfactory for thepractice of the invention to conduct the process of the invention atroom temperature. However, somewhat higher temperatures result in fasterreaction. In the most preferred embodiment of the invention,acetonitrile is employed as the solvent at a temperature between 0° C.and 80° C., preferably between room temperature and 80° C., mostpreferably between room temperature and 60° C.

Aprotic solvents suitable for preparing the dimetal sulfonyl amide salt(III) should be substantially free of water. Water causes the reactionto go in the wrong direction, for example to form CF₃SO₂NHNa and NaOH,and provides a route for making a sulfonate instead of an imide. In apreferred embodiment, it has been found satisfactory to employacetonitrile having water content less than or equal to ca 500 ppm, withwater content less than or equal to ca. 50 ppm more preferred.Acetonitrile is quite hygroscopic, and care should be taken in handlingto avoid water contamination from the atmosphere.

The preferred aprotic solvent for the preparation of the dimetalsulfonyl amide salt (III) comprises acetonitrile. Acetonitrile has beenfound to accelerate the conversion by a considerable amount over otheraprotic solvents. In neat acetonitrile, essentially quantitativeconversion is achieved in ca. 4 hours. In the presence of as little as5% acetonitrile in the THF taught by Xue,op. cit., essentiallyquantitative conversion is achieved in ca. 25 h. These results contraststarkly with the six days required under the conditions taught by Xue.

It is found that solvent selection has a tremendous effect on the rateof conversion, though most aprotic solvents will lead to high conversionover sufficient time. Acetonitrile is highly preferred. Other aliphaticand aromatic nitrites, while suitable, do not appear to be particularlybetter than the THF employed by Xue but may be employed as substitutesfor THF. Suitable nitrites include higher alkyl nitrites, dinitrilessuch as adiponitrile, benzonitrile, and the like. Other suitablesolvents include ethers, DMF, DMSO, DMAC, and amides. Combinations ofsuitable solvents are also suitable.

Any of the methods hereinabove, alone or in combination, provide ahighly purified form of the sufonyl amide salt (III) in dramaticdistinction over the practice of Xue. The highly purified form of(R²SO₂NM_(b))_(3-b)M′, (III), greater than 95% purity, which is readilyachieved using the methods herein described, is then suitable for use inthe process of the present invention producing pure imides, (I) or (II),at high yields, the purity thereof depending directly upon the purity of(III). Any of the methods of preparation herein described are capable ofproviding (III) in purities of greater than 95%.

The atmosphere to which the dimetal sulfonyl amide salt (III) is exposedshould be substantially free of water as well. Water vaporconcentrations of about 25 ppm have been found to be highly suitable.Higher levels of water vapor concentration can be tolerated, but itshould be understood that the higher the water vapor concentration ofthe atmosphere, the greater the contamination during subsequentreaction. As a general rule, the less water, the better, in whateverform.

The term “inert atmosphere” as used herein refers to an anhydrousatmosphere having a water vapor concentration of less than ca. 50 ppm.It is not meant to imply a non-oxidative atmosphere. Thus, the reactionsherein may be accomplished in desiccated air as well as in dry nitrogenor other non-chemically active gases. Dry nitrogen, however, ispreferred.

In a preferred method of preparation of the dimetal sulfonyl amide salt(III), CF₃SO₂NH₂ is dissolved at a concentration in the range of 5-10%by weight in acetonitrile in an inert atmosphere such as nitrogen. Athigher concentrations good mixing may become more difficult to maintainas the insoluble CF₃SO₂NNa₂ product begins to form, creating adispersion. Therefore at concentrations higher than about 10% by weight,other forms of agitation may be preferred over simple stirring, such asultrasonic agitation, or microfluidization such as may be achieved usinga MicroFluidizer™ available from Microfluidics, Inc., Newton, Mass.

While maintaining the inert atmosphere, NaH is added with agitationcontinued until the reaction is complete in about 4 hours. Hydrogen gasevolution rate, determined by any convenient method known in the art,has been found to be an effective indicator of reaction. The cessationof hydrogen gas flow signals completion of the reaction.

The amount of NaH added depends upon the particular requirements andintentions of the practitioner hereof. Adding a slight excess over thestoichiometric amount of NaH ensures complete conversion of theCF₃SO₂NH₂ or CF₃SO₂NHNa to CF₃SO₂NNa₂. However, this leaves CF₃SO₂NNa₂so prepared still contaminated with insoluble NaH from which it isdifficult to separate. However, it has been found that residual NaH islargely inert in the process of the invention and to the productsthereof. On the other hand, if the goal is to achieve the cleanestpossible CF₃SO₂NNa₂ then a slight deficit of NaH below thestoichiometric amount may be employed to ensure that the NaH will befully consumed. Employing a deficit of NaH will result in less thancomplete conversion of the CF₃SO₂NH₂ or CF₃SO₂NHNa to CF₃SO₂NNa₂. Thesoluble residual intermediary CF₃SO₂NHNa is easily washed away from theinsoluble CF₃SO₂NNa₂.

The dimetal sulfonyl amide salt (III) may be dried under vacuum atelevated temperature but the user must be aware of the possibility ofspontaneous and violent decomposition of the material. It is highlyrecommended to never handle this material in a totally dry state. It ishighly recommended to keep the material wet at all times. It seems thatthe smaller composition CF₃SO₂NNa₂ is less stable than the compositionsof higher molecular weight like C₄F₉SO₂NNa₂. A suitable temperaturedepends upon the specific composition thereof. The preferred CF₃SO₂NNa₂should be dried at a temperature preferably not higher than 80° C., mostpreferably not higher than 65° C. Certain of the compositions of theinvention, including the preferred CF₃SO₂NNa₂, have been observed toundergo certain decomposition aggressively when heated to thedecomposition threshold but it has also been observed at one occasionthat the preferred CF₃SO₂NNa₂ undergoes spontaneous decomposition atroom temperature. The compound is moisture sensitive and should behandled under anhydrous conditions. It is believed that the product issomewhat unstable, and potentially may be subject to explosivedecomposition.

EXAMPLES Example 1

CF₃SO₂NH₂was purchased from Tokyo Chemical Industry, Portland, Oreg.,(TCI) and dried and purified by two cycles of sublimation under a vacuumof about (0.1 Pa, 10⁻³ Torr), employing a water cooled (˜20° C.)cold-finger, and an oil bath at 80° C. Anhydrous acetonitrile waspurchased from EM Science Gibbstown, N.J., slurried with P₂O₅ anddistilled to ensure dryness, and stored over molecular sieves inside adry box until ready to be used. Sodium hydride (95%) was purchased fromAldrich Chemical.

Inside a model HE-63-P dry-box (Vacuum Atmosphere Company, Hawthorne,Calif.) having a dry nitrogen atmosphere, a round bottom flask wascharged with 30.003 g of the sublimed CF₃SO₂NH₂ and 750 ml of the driedacetonitrile. 9.003 g of the sodium hydride was slowly added over aperiod of 60 min while the reaction mixture was stirred with a magneticstir bar. The temperature of the reaction mixture increased from 21.6°C. to 50.5° C. during the addition process. The mixture was stirred atroom temperature for 20 h. After about 4-5 hours the reaction medium hadtaken on an opaque “creamy” appearance, and no further bubbling,indicative of the evolution of hydrogen, was observed.

The reacted mixture was filtered through a glass-filter (mediumporosity) inside the dry-box. The white solid was washed three timeswith 100 ml of the anhydrous acetonitrile, transferred from the filterto a Schlenk flask and dried under vacuum (1 Pa, 10⁻² Torr) at roomtemperature for 5 h, still in the dry box. Approximately 10% of thefiltrate was lost in transferring from the filter to the Schlenk flask.The Schlenk flask was sealed, removed from the dry-box, and subject tofurther evacuation under oil pump vacuum (0.1 Pa, 10⁻³ Torr) for 15 h atroom temperature. The Schlenk flask was then immersed in an oil bath setat 50° C. and held for four hours at which time the bath was heated to65° C. and the 20 Schlenk flask was held therein for an additional 20 hwhile still subject to evacuation under oil pump vacuum (0.1 Pa, 10⁻³Torr). Afterwards, the CF₃SO₂NNa₂ was only handled inside the dry-box.

30.0 grams of product were isolated. The product decomposed at 110° C.while generating large amounts of a gas.

It has been observed at one occasion that the preferred CF₃SO₂NNa₂undergoes spontaneous decomposition at room temperature and it istherefore recommended to not dry this material but instead keep it as asuspension at all times.

Example 2

Inside the dry box of Example 1, a flask was charged with 5.142 gC₄F₉SO₂NH₂ made from C₄F₉SO₂F and NH₃ according to the method ofMeuBdoerffer et al, op. cit., and 100 ml of anhydrous acetonitrileprepared as in Example 1. 0.784 g NaH (Aldrich) was slowly added over aperiod of 5 min. The mixture was stirred at room temperature for 24 hwithout observation. Insoluble C₄F₉SO₂NNa₂ had precipitated at thebottom of the flask. The reaction mixture was filtered through a glassfilter (fine porosity) and the white residue was washed three times with50 ml of anhydrous acetonitrile. The residue was collected from thefilter and placed in a Schlenk-flask. Afterwards, the material wasbrought outside the dry-box and dried under oil pump vacuum (0.1 Pa,10⁻³ Torr) for 24 h at an oil bath temperature of 65° C. C₄F₉SO₂NNa₂ wasonly handled inside the dry-box. 4.37 g of product were isolated.

It has been observed at one occasion that the preferred CF₃SO₂NNa₂undergoes spontaneous decomposition at room temperature and it istherefore recommended to not dry this material but instead keep it as asuspension at all times.

Example 3

Employing the reagents and equipment of Example 1, inside the dry-box3.123 g of the sublimed CF₃SO₂NH₂ was dissolved in 100 ml of theanhydrous acetonitrile in a round-bottom flask. 1.127 g of the sodiumhydride was slowly added to form a first reaction mixture. Addition ofNaH took place over a period of 10min while the first reaction mixturewas stirred with a magnetic stirring bar at room temperature. After 3 h,no fluorine could be detected by ¹⁹F NMR in the solution indicatingcomplete conversion of CF₃SO₂NH₂ to CF₃SO₂NNa₂, thereby forming amixture of CF₃SO₂NNa₂ and acetonitrile, with some residual NaH.

CF₂═CFOCF₂CF(CF₃)OCF₂CF₂SO₂F (PSEPVE) prepared according to the methodof Connolly et al., U.S. Pat. No. 3,282,875, was slurried with P₂O₅ anddistilled. 10.002 g of the thus-treated PSEPVE was added to the mixtureof CF₃SO₂NNa₂ and acetonitrile prepared as hereinabove to form a secondreaction mixture. The second reaction mixture was stirred at roomtemperature. After 10 min, the mixture turned clear, indicative ofcomplete reaction of the CF₃SO₂NNa₂, and then slightly cloudy,indicative of the precipitation of the NaF by-product After 30 minutesfluorine NMR confirmed a substantial concentration of the imidized formof PSEPVE. The reacted mixture was centrifuged and then filtered througha glass filter (medium porosity). The residue was washed with 100 ml ofanhydrous acetonitrile. All volatiles were removed under vacuum of 0.1Pa, 10⁻³ Torr at room temperature and the slightly beige residue washeated to 110° C. for 16 h at 0.1 Pa, 10⁻³ Torr. Yield was 9.494 g.

¹⁹F NMR in CD₃CN confirmed the structure

CF₂═CFOCF₂CF(CF₃)OCF₂CF₂SO₂N(Na)SO₂CF₃.

¹⁹F NMR in CD₃CN/Freon-11

(CF₂ ^(A,A′)═CF^(B)OCF₂ ^(C)CF^(D)(CF₃ ^(E))OCF₂ ^(F)CF₂^(G)SO₂N(Na)SO₂CF₃ ^(H)): −112.6, −120.9 ppm (A, 1F, A′, 1F), −135.7 ppm(B, 1F), −78.0 ppm (CF₂, C, 2F), −144.2 ppm (CF, D, 1F), −79.1 ppm (CF₃,E, 3F), −83.7 ppm (CF₂, F, 2F), −116.0 ppm (CF₂, G, 2F), −78.9 ppm (CF₃,H, 3F).

MS: Negative electron spray; 574.14, M-Na.

Example 4

Inside the dry-box of Example 1, a round bottom flask was charged with5.027 g of the C₄F₉SO₂NH₂ made from C₄F₉SO₂F and NH₃ according to themethod of MeuBdoerffer et al, op.cit., and 100 ml of anhydrousacetonitrile prepared as in Example 1. 0.890 g of sodium hydride(Aldrich) was slowly added to form a first reaction mixture. Addition ofNaH took place over a period of 10 min while the reaction mixture wasstirred at room temperature with a magnetic stir bar. After 22 h ofsiring, no fluorine could be detected by ¹⁹F NMR in the solutionindicating complete conversion, thereby forming a mixture of C₄F₉SO₂NNa₂in acetonitrile, contaminated by some residual NaH.

7.797 g of the PSEPVE of Example 3 was added to the mixture ofC₄F₉SO₂NNa₂ and acetonitrile prepared hereinabove to form a secondreaction mixture. The second reaction mixture was stirred at roomtemperature. After 10 min, the mixture turned clear, indicative ofcomplete reaction of the CF₃SO₂NNa₂, and then slightly cloudy,indicating the precipitation of the NaF by-product. NMR of the reactionmixture taken after 30 min confirmed the substantial presence of theimidized form of PSEPVE. The reaction mixture was centrifuged and thenfiltered through a glass filter (medium porosity). The residue waswashed with 100 ml of anhydrous acetonitrile. All volatiles were removedunder vacuum and the slightly beige residue was heated to 110° C. for 16h at 1 Pa, 10⁻³ Torr. Yield was 8.358 g.

¹⁹F NMR in CD₃CN confirmed the structure

CF₂═CFOCF₂CF(CF₃)OCF₂CF₂SO₂N(Na)SO₂(CF₂)₃CF₃

¹⁹F NMR in CD₃CN/Freon-11

(CF₂ ^(A,A′)═CF^(B)OCF₂ ^(C)CF^(D)(CF₃ ^(E))OCF₂ ^(F)CF₂ ^(G)SO₂N(Na)SO₂CF₂ ^(H)CF₂ ^(I)CF₂ ^(J)CF₃ ^(K)): −112.6, −120.7 ppm (A, 1F,A′, 1F), −135.6 ppm (B, 1F), −78.0 ppm (CF₂, C, 2F), −144.1 ppm (CF, D,1F), −79.1 ppm (CF₃, E, 3F), −83.7 ppm (CF₂, F, 2F), −115.9 ppm (CF₂, G,2F), −112.6 ppm (CF₂, H, 2F), −120.6 ppm (CF₂, I, 2F), −125.8 ppm (CF₂,J, 2F), −79.1 ppm (CF₃, K, 3F).

MS: Negative electron spray; 723.98, M-Na.

Example 5

Benzonitrile (Aldrich)was dried by mixing with P₂O₅ and then distilling.Employing reagents and equipment of Example 1, inside the dry-box 3.008g of the sublimed CF₃SO₂NH₂ was dissolved in 90 ml of the driedbenzonitrile in a round-bottom flask To form a first reaction mixture,1.018 g of the sodium hydride was slowly added while the reactionmixture was stirred with a magnetic stirring bar at room temperature.The reaction mixture changed its appearance after 10 min. A whiteprecipitate was formed causing a thickening of the slurry. Shortlyafter, the reaction mixture changed its color to yellow. After 60 min,the reaction mixture was red. After 6 h, fluorine could still bedetected by ¹⁹F NMR in the solution. After a total of 24 h at roomtemperature, 8.511 g of PSEPVE of Example 3 was added, thereby forming asecond reactions mixture. The second reaction mixture was stirred atroom temperature. The color changed from red to yellow. ¹⁹F NMR in CD₃CNafter 2 h confirmed the formation of the structureCF₂═CFOCF₂CF(CF₃)OCF₂CF₂SO₂N(Na)SO₂CF₃.

Example 6

In this Example, an apparatus was employed for determining the volume ofhydrogen gas evolved by the reaction as a function of time. Theapparatus is depicted in FIG. 1. One neck of a three necked round bottomflask, 1, holding a magnetic stirring bar, 2, was fitted with a solidreactant addition device SRAD, 3, having a 75° angle to be employed forfeeding a solid to the flask. A second neck was fitted with athermocouple probe, 4, and a third neck was fitted with a stopcock, 5.The stopcock, 5, was connected via a 4 cm piece of Tygon® tubing, 6, toan Aldrich Safe-purge (TM) valve, 7, containing mineral oil. TheSafe-purge valve, 7, was connected via a rubber hose, 8, to awater-filled 250 ml graduated cylinder, 9, that is deployed upside-downin a water-filled 600 ml beaker, 10. In operation liquid reactants werecharged to the flask through any of the necks, SRAD, 3, was charged withthe desired amount of solid reactant and reaffixed to the flask, 1, inthe downward-pointing position shown in the figure. The beaker, 10, wasfilled to about 50% of capacity with water while the graduated cylinder,9, was filled completely with water. The stopcock, 5, was opened, andthe adaptor, 3, was inverted thus delivering the solid reactant to thereactants in the flask and thereby initiating the reaction. As hydrogenwas evolved from the reaction it displaces the water from the graduatedcylinder providing a volumetric means for determining the rate and totalamount of hydrogen evolution.

Employing the methods and material of Example 1, inside the dry-box,0.546 g of the sublimed CF₃SO₂NH₂ was dissolved in 100 ml of theanhydrous acetonitrile in the three neck round bottom flask of FIG. 1.0.213 g of the sodium hydride was carefully placed in the SRAD. Theflask was carefully brought outside the dry box and connected to theremainder of the apparatus of FIG. 1. After all connections had beenestablished, the stopcock to the reaction flask was opened. The reactionmixture was stirred at room temperature and the SRAD was invertedthereby feeding the NaH to the solution in the flask. Immediately, areaction could be observed. 80 ml of gas were collected over a period of5 min. The temperature of the reaction mixture increased from 23° C. to26° C. Over the next 120 min, the formation of gas slowed down and 74 mlof gas were collected in the graduated cylinder. During this period, theappearance of the reaction mixture changed. The fine residue in thereaction mixture changed to a thicker precipitate that settled easily tothe bottom of the flask when the stirring was stopped. The reactionmixture was stirred for another hour at room temperature, 10 ml ofadditional gas were collected during this period. The flask was broughtinto the dry box and a sample of the solution was submitted for NMR. Nofluorine could be detected, indicating the complete conversion ofCF₃SO₂NHNa into insoluble CF₃SO₂NNa₂.

Example 7

Excess CF₃SO₂NH₂ and NaOH were reacted in water to prepare CF₃SO₂NNaH.Water and excess CF₃SO₂NH₂ were removed under vacuum (0.1 Pa, 10⁻³ Torr)at 70° C.; the residue was dried for 16 h at 0.1 Pa, 10⁻³ Torr at 110°C. Following the procedures of Example 1, inside the dry box, a 250 mltwo neck round bottom flask with a magnetic siring bar was charged with1.034 g of the CF₃SO₂NNaH. The material was dissolved in 100 ml ofanhydrous acetonitrile of Example 1. The procedures of Example 10 werefollowed but the three necked flask was replaced by the two-necked flaskand the thermocouple was omitted. The reaction mixture was stirred atroom temperature and the SRAD was inverted thereby feeding the NaH tothe solution in the flask. No immediate reaction could be observed. Overthe first 150 min, only a total of 10 ml of an evolving gas could becollected. After 150 min, the formation of gas started. Over the next105 min, additional 135 ml of gas were collected in the graduatedcylinder. During this period, the appearance of the reaction mixturechanged. The fine residue in the reaction mixture changed to a thickerprecipitation that settled easily at the bottom of the flask when thestirring was stopped. The reaction mixture was stirred for another 14 hat room temperature. 10 ml of additional gas were collected during thisperiod. The flask was brought into the dry box and a sample of thesolution was submitted for NMR No fluorine could be detected, indicatingthe complete conversion of CF₃SO₂NHNa into insoluble CF₃SO₂NNa₂.

Example 8

Following the procedure of Example 10, inside the dry-box, a 250 mlthree neck round bottom flask was charged with 75 ml of anhydrousacetonitrile prepared as in Example 1. 0.189 g NaH was placed in theSRAD. 0.879 g of the CF₃SO₂NHNa of Example 10 was dissolved in 25 mlacetonitrile prepared as in Example 1 and placed in an addition funnelwhich substituted for the thermocouple of Example 10. After the requiredconnections were made, the reaction mixture was stirred at roomtemperature and the NaH was immediately added to the solvent. 6 ml ofgas were collected over a period of 3 h. The CF₃SO₂NHNa solution wasadded and the reaction mixture was continued to be stirred at roomtemperature. 1 h 45 min after the addition of the CF₃SO₂NHNa, anadditional 4 ml of gas had been collected. The reaction mixture turnedslightly yellow. 4 h after the addition of the CF₃SO₂NHNa, the reactionseemed to start. 6 h and 40 min after the addition of the mono-sodiumsolution, a total of 80 ml of gas since the addition had been collected.The reaction mixture was sired for another 14 h 30 min. A total of 116ml gas had been collected. 103 ml are the expected amount The flask wasbrought into the dry-box and an NMR sample was collected from thesolution. Only a trace of a fluorine signal at −80.6 ppm could bedetected, indicating the conversion of CF₃SO₂NHNa into insolubleCF₃SO₂NNa₂.

2.120 g PSEPVE was added to the now bright yellow solution, containing ayellowish solid. The reaction mixture turned orange and after 15 minstirring at room temperature, the reaction mixture turned clear. A fineprecipitate formed. An NMR sample was collected after 1 h showing theformation of the product CF₂═CFOCF₂CF(CF₃)OCF₂CF₂SO₂N(Na)SO₂CF₃ andexcess PSEPVE.

Comparative Example 1

Inside the dry-box of Example 1, a flask was charged with 0.93 g ofCF₃SO₂NHNa from Example 11, 0.135 g NaH (Aldrich) and 20 ml of anhydrousTHF (Aldrich; distilled off Na metal). The reaction mixture was stirredfor 4 h at room temperature and was then filtered through a glass filter(fine porosity). The filtrate was collected in a flask and broughtoutside the dry-box. All solvents were removed under vacuum (0.1 Pa,10⁻³ Torr) and the residue was heated to 65° C. for 24 h at 0.1 Pa, 10⁻³Torr. 0.862 g (5.04 mmol) of CF₃SO₂NHNa were recovered, corresponding to92.6% of the staring material. The dried material was brought into thedry-box and 50 ml of anhydrous acetonitrile were added because it issuspected that CF₃SO₂NNa₂ is slightly soluble in THF. The majority ofthe material was dissolved in the acetonitrile and only a slight traceof a solid could be observed in the solution. It was not attempted toseparate this residue. It should be safe to assume that less than 10% ofthe CF₃SO₂NHNa have been converted to CF₃SO₂NNa₂ after 4 h in THF atroom temperature.

Example 9

Following the procedures of Example 11, inside the dry-box, the roundbottom flask was charged with 0.866 g of the CF₃SO₂NHNa of Example 11.The material was dissolved in 100 ml of anhydrous THF (Aldrich;distilled from Na metal; stored over molecular sieves inside thedry-box). 0.171 g of NaH was placed in the SRAD. After the requiredconnections were made according to Example 10, the reaction mixture wasstirred at room temperature and the NaH was added to the solution. Noobvious reaction could be observed. A total of 113.3 ml of collectedhydrogen would represent complete conversion under normalizedconditions. The gas collected as a function of time is shown in Table 1.

TABLE 1 Elapsed time Gas Collected estimated % (after addition of NaH)(ml) conversion  0 h 45 min 4 3.5  2 h 30 min 10 8.8  5 h 45 min 10 8.8 21 h 45 min 18 15.9  26 h 15 min 25 22.1  32 h 45 min 28 24.7  47 h     38 33.6  49 h 15 min 43 38.0  53 h 30 min 47 41.6  84 h 45 min 53 46.9 86 h 45 min 55 48.6  97 h 15 min 65 57.5 118 h      78 69.0 122 h 15min 85 75.2 139 h 45 min 110 97.3 142 h   114 100.5

The reaction was completed after six days at room temperature. Thereaction flask was brought inside the dry-box.

2.511 g PSEPVE was added to the colorless reaction mixture thatcontained a white solid. After 10 min stirring at room temperature, thereaction mixture turned clear. A fine precipitation formed. An NMRsample was collected after 1 h showing the formation of the productCF₂═CFOCF₂CF(CF₃)OCF₂CF₂SO₂N(Na)SO₂CF₃ and excess PSEPVE.

Example 10

Following the procedure of Example 11, inside the dry-box, the roundbottom flask was charged with 0.633, of the CF₃SO₂NHNa of Example 11.The material was dissolved in 100 ml of anhydrous acetonitrile preparedas in Example 1. 0.103 g of NaH was placed in the SRAD. After therequired connections were made, the reaction mixture was stirred andheated by immersing the flask in an oil-bath set at 50° C. The reactionmixture was heated for 2 h and the pressure was allowed to equalizeinside the flask. No pressure was released through the bubbler for 30min. After 2 h of heating, the NaH was added to the solution. No obviousreaction could be observed for 20 min. After 20 min., gas was releasedfrom the reaction mixture. Evolution of ca. 83 ml of gas was calculatedto correspond to complete conversion.

TABLE 2 Elapsed time Gas Collected (after addition of NaH) (ml) 0 h 20min 0 0 h 25 min 25 0 h 30 min 71 0 h 35 min 85 1 h  0 min 91

The formation of gas stopped after 1 hour. The gas collection record isshown in Table 2. The reaction mixture was stirred for another hour at50° C. oil bath temperature with no further accumulation of gas. Thereaction flask was brought inside the dry-box and an NMR sample wastaken from the clear solution above the white residue. Only a trace of afluorine signal at −80.6 ppm could be detected in the noise of the NMRspectrum, indicating the conversion of CF₃SO₂NHNa into insolubleCF₃SO₂NNa₂.

1.740 g PSEPVE was added to the colorless reaction mixture thatcontained a white solid. The reaction mixture turned yellow and after 10min stirring at room temperature, the reaction mixture turned clear. Afine precipitation formed. An NMR sample was collected after 1 h showingthe formation of the product CF₂═CFOCF₂CF(CF₃)OCF₂CF₂SO₂N(Na)SO₂CF₃ andexcess PSEPVE.

Example 11

Following the procedure of Example 10, the flask was charged with 1.195g of the CF₃SO₂NHNa which was dissolved in a mixture of 95 ml of THF and5 ml of anhydrous acetonitrile. 0.195 g of the NaH were placed in theSRAD. After connection to the remainder of the apparatus of Example 10,the NaH was added to the reactants in the flask. No immediate reactioncould be observed. Over the first 1 h, only a total of 4 ml of gas wasevolved. Over the next 5 h, only a total of 7 ml of the expected 157 ml.Hydrogen gas had been collected. The reaction mixture was stirred for atotal of 25 h at room temperature without further observation. 160 ml ofgas were collected during this period. 4.500 g PSEPVE was added to thecolorless reaction mixture that contained a white solid. The reactionmixture did not change its color and after 10 min stirring at roomtemperature, the reaction mixture turned clear. A fine precipitationformed. An NMR sample was collected after 1 h showing the formation ofthe product CF₂═CFOCF₂CF(CF₃)OCF₂CF₂SO₂N(Na)SO₂CF₃ and excess PSEPVE.

Example 12

Employing the reagents and equipment of Example 1, inside the dry-box3.033 g of the sublimed CF₃SO₂NH₂ was placed in a round bottom flask anddissolved in 50 ml of the anhydrous acetonitrile. 1.511 g of CaH₂(Aldrich; 90-95%) was added. The reaction mixture was stirred with amagnetic stir bar at room temperature for 48 h. No fluorine could bedetected in the reaction mixture after this time period by NMR,indicating the complete conversion of CF₃SO₂NH₂ to (CF₃SO₂NCa)₂.

9.461 g of distilled PSEPVE was added and the reaction mixture wasstirred at room temperature. No conversion to the product could beobserved after 24 h at room temperature.

The reaction mixture was heated to 60° C. for 7 days. The reactionmixture was filtered inside the dry-box through a glass filter (mediumporosity) and the flask with the collected solution was brought outsidethe dry-box. All volatiles were removed under vacuum (0.1 Pa, 10⁻³ Torr)and the beige residue was heated to 100° C. at 0.1 Pa, 10⁻³ Torr for 16h. ¹⁹F NMR in CD₃CN confirmed the structure(CF₂═CFOCF₂CF(CF₃)OCF₂CF₂SO₂NSO₂CF₃)₂Ca.

Yield was 1.729 g.

¹⁹F NMR in CD₃CN

(CF₂ ^(A,A′)═CF^(B)OCF₂ ^(C)CF^(D)(CF₃ ^(E))OCF₂ ^(F)CF₂ ^(G)SO₂NSO₂CF₃^(H))₂Ca: −114.3, −122.7 ppm (A, 1F, A′, 1F), −137.3 ppm (B, 1F), −79.5ppm (CF₂, C, 2F), −145.9 ppm (CF, D, 1F), −80.9 ppm (CF₃, E, 3F) −85.5ppm (CF₂, F, 2F), −117.6 (CF₂, G, 2F), −80.6 ppm (CF₃, H, 3F).

MS: Negative electron spray; 573.98, (M-Ca)/2.

Example 13

Inside the dry-box, a round bottom flask was charged with 3.051 g, ofthe CF₃SO₂NH₂ prepared in the manner of Example 1 and 100 ml ofanhydrous acetonitrile prepared as in Example 1. 1.068 g of the NaH(Aldrich) was added slowly over a period of 5 min. The mixture wasstirred at room temperature for 26 h inside the dry-box and checkedperiodically by fluorine NMR until no fluorine could be detected. 3.27 gC₆H₅SO₂F used as received from Aldrich was added to the flask. Thereaction mixture thus formed was stirred at room temperature for 144 h.The reaction mixture was centrifuged and all volatiles were removed fromthe reaction solution. The residue was dried at 110° C. for 24 h at 0.1Pa, 10⁻³ Torr. The residue was redissolved in 100 ml of anhydrousacetonitrile and filtered through a paper filter. All volatiles wereremoved from the solution. The residue was dried at 110° C. for 16 h at0.1 Pa, 10⁻³ Torr. NMR in CD₃CN and mass spec. confirmed the structurePhSO₂N(Na)SO₂CF₃.

Yield was 4.284 g.

¹⁹F NMR in CD₃CN: −79.9 ppm (CF₃, 3F). ¹H NMR in CD₃CN: 7.90 ppm (2H),7.54 ppm (3H).

MS: negative electron spray; 288.09, M-Na.

Example 14

As in Example 1, a round bottom flask was charged with 3.082 g of theCF₃SO₂NH₂ prepared as in Example 1 and 100 ml of anhydrous acetonitrileprepared as in Example 1. 1.134 g of the NaH (Aldrich) was added slowlyover a period of 5 min. The mixture was stirred at room temperature for16 h inside the dry-box. No fluorine could be detected by NMR 2.025 g ofCH₃SO₂F (Aldrich, as received) was added. The reaction mixture thusformed was stirred at room temperature for 2 h. The reaction mixture wascentrifuged and all volatiles were removed. The residue was dried at110° C. for 24 h at 0.1 Pa, 10⁻³ Torr. The residue was redissolved in100 ml of anhydrous acetonitrile and filtered through a paper filter.All volatiles were removed from the solution. The residue was dried at110° C. for 16 h at 0.1 Pa, 10⁻³ Torr. Yield was 4.20 g.

NMR in CD₃CN and mass spec. confirmed the structure CH₃SO₂N(Na)SO₂CF₃.¹⁹F NMR in CD₃CN: −79.7 ppm (CF₃, 3F). ¹H NMR in CD₃CN: 2.966 ppm (3H).MS: negative electron spray; 226.06, M-Na.

Example 15

A 400 mL Hastelloy autoclave prechilled to <−20° C. was charged withPSEPVE (150 g) and 15 mL of 0.17 M hexafluoropropylene oxide dimerperoxide. The vessel was closed, evacuated, then filter charged withvinylidene fluoride (64 g) and CO₂ (150 g), and shaken at roomtemperature for 18 hr. Excess pressure was released and the viscousresidue was analyzed by ¹⁹F NMR (acetone d₆) which clearly indicatedresidual monomer. Estimated conversion of PSEPVE was ca 60%. The entiresample was devolatilized at 100° C. (0.5 mm) for several hours. Samplewas a rather tough rubber, deformable by application of force. It didnot flow significantly at room temperature under its own weight.

¹⁹F NMR (acetone d₆): +45.5 (s, a=0.91), −77.5 to −79.8 (m, a=7.00), −91to −95.5 (m, a=4.038), −108 to −115.9 (m, a=4.680), −121.8, −122.3, and−122.8 (series of broadened m's. a=1.651), −124 to −127 (bd m's,a=0.766), −129.5 (s, a=0.0244, assigned to internal CF₂ ofCF₃CF₂CF₂OCF(CF₃)-fragment (end group), −144 (bm, CF from PSEPVE sidechains). Integration was consistent with 24.5 mol % PSEPVE. Integrationof end groups from dimer peroxide fragments, assuming that all ends areof this type, gives an estimate of M_(n) for the copolymer as 106,000.¹H NMR showed only broad signal 3.5-2.7.

4.47 g of the copolymer so prepared was dried at 0.1 Pa, 10⁻³ Torr for24 h at 100° C. 100 ml of anhydrous THF was added to the polymer and thereaction mixture was refluxed for 16 h to dissolve the polymer. 1.344 gof the CF₃SO₂NNa₂ prepared in Example 1 were added at room temperatureover a period of 2 h. The reaction mixture was stirred at roomtemperature. The reaction mixture turned cloudy after 3 h. An additional0.418 g of CF₃SO₂NNa₂ was added over the next 6 days. After all theCF₃SO₂NNa₂ was added, the reaction mixture so formed was heated to 50°C. After 3 days at 50° C., ¹⁹F NMR indicated that the reaction wascomplete.

The reaction mixture was brought outside the dry-box and centrifuged. Aslightly brown solution could be separated from a dark brown residue.Analysis of the residue showed that it was mostly NaF and excessCF₃SO₂NHNa starting material. All volatiles were removed from thecombined solutions and the beige residue was heated to 110° C. at 0.1Pa, 10⁻³ Torr for 16 h. Yield is 3.8 g. ¹⁹F NMR in d₈-THF confirmedcomplete conversion of the sulfonyl fluoride groups of the polymer toimide. ¹⁹F NMR Residue in d₈-THF; −79 to −85 ppm (CF₃SO₂, CF₃(CF),2×CF₂O, 10 F), −90 to −135 ppm (CF₂SO₂, VF₂ fluorines), −146.0 ppm(CF(CF₃), 1F); integration gives 28 mol % PSEPVE-imide in the polymer.¹H NMR Residue in d₈-THF: 2 to 3.8 ppm VF₂ protons.

Example 16

CH₂═CHCH₂CF₂CF₂OCF₂CF₂SO₂F was synthesized according to the teachings ofGuo et al., Huaxue Xuebao (1984), 42(6), 592-5.

As in Example 1, a round bottom flask was charged with 2.02 g ofCF₃SO₂NNa₂ prepared as in Example 1 and 60 ml of anhydrous acetonitrileprepared as in Example 1. 3.73 g CH₂═CHCH₂CF₂CF₂0CF₂CF₂SO₂F was addeddrop wise over a period of 5 min. After 20-25 min, the mixture turnedclear and then generated a precipitation. The mixture was stirred for 3h at room temperature. The reaction mixture was filtered through a paperfilter inside the dry box. All volatiles were removed and the whiteresidue was heated to 100° C. for 16 h at 0.1 Pa, 10⁻³ Torr. Yield was3.635 g. ¹⁹F NMR in CD₃CN confirmed the structureCH₂═CHCH₂CF₂CF₂OCF₂CF₂SO₂N(Na)SO₂CF₃.

¹⁹F NMR in CD₃CN:

CH₂═CHCH₂CF₂ACF₂BOCF₂CCF₂DSO,N(Na)SO₂CF₃E: −80.60 ppm (CF₃, E, 3F),−82.77 ppm (CF₂, C, 2F), −88.90 ppm (CF₂, B, 2F), −118.31 ppm (2×CF₂,A+D, 4F).

¹H NMR in CD₃CN: CH₂A=CHBCH₂CCF₂CF₂OCF₂˜: 2.87 ppm (CH₂, C, tdt, 2H),5.26 ppm (CH₂, A, 2F) and 5.74 ppm (CH₂, B, 1F).

I claim:
 1. A process comprising: contacting in a liquid dispersion orsolution a composition comprising a metal sulfonyl amide saltrepresented by the formula: R²SO₂NM_(b) wherein R² is aryl, fluoro-aryl,or XCF₂— where X is H, halogen, fluorinated or non-fluorinated linear orcyclic alkyl radicals having 1-10 carbons, optionally substituted by oneor more ether oxygens, b=1 or 2, M is an alkaline earth where b is 1 oran alkali metal where b is 2; with a non-polymeric sulfonyl fluoridecomposition represented by the formula, R¹(SO₂F)_(m) wherein m=1 or 2,where when m=1, R¹ is a fluorinated or non-fluorinated, saturated orunsaturated hydrocarbyl radical except perfluoroolefin having 1-12carbons optionally substituted by one or more ether oxygens, or tertiaryamino; or, when m=2, R¹ is a fluorinated or non-fluorinated, saturatedor unsaturated hydrocarbylene, except perfluoroalkylene, radical having1-12 carbons optionally substituted by one or more ether oxygens; orwith a polymeric sulfonyl fluoride composition comprising monomer unitsrepresented by the formula: —[CZ₂CZ(R³SO₂F)]— wherein R³ is a diradicalselected from the group consisting of fluorinated or non-fluorinatedalkenyl, including oxyalkenyl or fluorooxyalkenyl, and each Z isindependently hydrogen or halogen, and need not be the same; and,causing them to react to form a non-polymeric imide compositionrepresented by the formula: R¹(SO₂NM_(b)SO₂R²)_(m) or, in thealternative, a polymeric imide composition comprising monomer unitsrepresented by the formula, (—[CZ₂CZ(R³SO₂N(M)SO₂R²)]—)y.
 2. The processof claim 1 wherein m=1.
 3. The process of claim 1 further comprising aninert, aprotic organic liquid.
 4. The process of claim 3 wherein theorganic liquid is an ether.
 5. The process of claim 4 wherein the etheris tetrahydrofuran.
 6. The process of claim 1 wherein R² is aperfluoroalkyl radical.
 7. The process of claim 6 wherein R² is atrifluoromethyl radical.
 8. The process of claim 1 wherein M is analkali metal, b=2.
 9. The process of claim 8 wherein M is sodium. 10.The process of claim 2 wherein R¹ is a perfluorovinyl ether radical. 11.The process of claim 10 wherein the perfluorovinyl ether radical isrepresented by the formula: CF₂═CF—O—[CF₂CF(R⁴)—O_(z)]_(a)—CF₂CF₂—wherein R⁴ is F or perfluoroalkyl having 1-4 carbons, z=0 or 1, anda=0-3.
 12. The process of claim 11 wherein R⁴ is trifluoromethyl, z=1,and a=0 or
 1. 13. The process of claim 1 wherein Z is F.
 14. The processof claim 1 wherein R³ is a perfluorooxyalkenyl radical.
 15. The processof claim 14 where R³ is a perfluorooxyalkenyl radical represented by theformula: —O—[CF₂CF(R⁴)—O_(z)]_(a)—CF₂CF₂— wherein R⁴ is F orperfluoroalkyl having 1-4 carbons, z=0 or 1, and a=0-3.
 16. The processof claim 15 wherein R⁴ is trifluoromethyl, z=1, and a=0 or
 1. 17. Theprocess of claim 1 wherein the sulfonyl fluoride polymer compositionfurther comprises comonomer units derived from the group consisting offluorinated, but not perfluorinated, olefins, non-fluorinated olefins,fluorinated vinyl ethers, non-fluorinated vinyl ethers, and mixturesthereof.
 18. The process of claim 17 wherein the comonomer units arederived from the group consisting of ethylene, perfluoroalkyl vinylether, vinylidene fluoride, and vinyl fluoride, and mixtures thereof.19. The process of claim 18 wherein the comonomer units comprisevinylidene fluoride.
 20. The process of claim 19 wherein the vinylidenefluoride is at a concentration of at least 50 mol % in the sulfonylfluoride polymer composition.
 21. The process of claim 1 wherein themonomer units represented by the formula —[CZ₂CZ(R³SO₂F)]— are presentin the sulfonyl fluoride polymer at a concentration of up to 50 mol %.22. The process of claim 21 wherein the monomer units represented by theformula —[CZ₂CZ(R³SO₂F)]— are present in the sulfonyl fluoride polymerat a concentration of up to 20 mol %.
 23. The process of claim 9 furthercomprising the step of performing an ion exchange to form the lithiumimide.
 24. The process of claim 23 wherein the ion exchange is performedby contacting the sodium imide with organic lithium chloride solution.25. The process of claim 1 wherein the composition comprising thedimetal sulfonyl amide salt comprises at least 50 mol % of said dimetalsulfonyl amide salt.
 26. The process of claim 25 wherein the compositioncomprises at least 90 mol % of said dimetal sulfonyl amide salt.
 27. Theprocess of claim 1 wherein the dimetal sulfonyl amide salt is contactedwith the non-polymeric sulfonyl fluoride composition causing them toreact to form the non-polymeric imide composition.
 28. The process ofclaim 1 wherein the dimetal sulfonyl amide salt is contacted with thepolymeric sulfonyl fluoride composition causing them to react to formthe polymeric imide composition.
 29. The process of claim 18 wherein thesulfonyl fluoride polymer composition further comprises a termonomerunit derived from a perfluoro-olefin.
 30. The process of claim 29wherein the perfluorolefin is tetrafluoroethylene, hexafluoropropyleneor a combination thereof.